With the persistently progressive electronic technology, computer science is also widely applied in various fields. The current computer has greatly advanced in function and speed and has been able to process massive and complicated data. In addition to having superior performance, the current computer is also getting slimmer and compacter. Especially, a miniature or vehicular computer usually carries many complicated electronic elements in a very limited space. Operating electronic elements inevitably generate heat, which influences the stability of the system. Thus, heat dissipation technologies are developed to solve such a problem.
Heat dissipation technologies include active cooling technologies and passive cooling technologies. The active cooling technologies utilize external power to drive a cooling device, such as a cooling fan or a cooling water pump. The passive cooling technologies utilize a heat dissipation device made of a heat conduction material, such as heat dissipation fins or heat dissipation pipes, to dissipate heat into air. To achieve a better heat dissipation effect, a single electronic device commonly adopts both active cooling elements and passive cooling elements. For a single electronic device, such a method may really promote heat dissipation efficiency. However, for an electronic apparatus having many electronic devices elaborately arranged, too many heat dissipation elements is unfavorable to miniaturization and compactness. Besides, a plurality of cooling fans operating at high speed generates considerable noise and vibration or even causes internal air turbulence, which may contrarily impair draining heat.
U.S. Pat. No. 7,177,154 and publication No. 2006/0056155 respectively disclosed two computers without using any cooling fan to solve the problems caused by high-speed cooling fans. The former utilizes at least one heat conduction unit to conduct to the housing the heat generated by heat-generating elements. The latter thermally couples the heat-generating elements to heat dissipation plates externally arranged on the housing. As the two conventional technologies mentioned above do not adopt any cooling fan, they can noiselessly lower the interior temperature of a computer. However, the pure passive cooling technologies are limited by the heat conductivity of heat conduction materials. When they are used in an electronic device generating considerable heat or a miniature electronic device, the heat dissipation speed may be smaller than the heat generating speed. Hence, they cannot be extensively applied to all electronic devices.